A number of difficulties are associated with image scanner technology. Specifically, the transformation of an analog signal of the image into a digital signal of the image is accompanied by a number of difficulties. First, the analog signal is subject to variation with heat, humidity, and other external factors which affect the quality of the resultant digital data. Next, the analog signal includes a noise portion which is transferred into the digital signal in the absence of proper processing. Another problem with analog signal manipulation in slide scanners is the saturation of analog devices within the scanner. These problems often result in a signal which includes erroneous data in a non-linear form. To correct this data requires a great deal of processing power.
By calibrating the sensor board, or analog electronics, on a scanner, an improved signal may be obtained. As a result, subsequent signal processing is reduced, therefore a smaller processor may be employed.
Calibration of a scanner is difficult since many elements associated with the scanner have interdependent relationships. Thus, adjusting one element will result in changes to other elements. Prior art attempts at calibrating scanners have relied upon a one-pass approach to calibrating elements.